package org.eclipse.swt.widgets;
import org.eclipse.swt.*;
import org.eclipse.swt.graphics.*;
/*
* Licensed Materials - Property of IBM,
* (c) Copyright IBM Corp. 1998, 2000 All Rights Reserved
*/
/**
* This class emulates a windows TabItem, which represents a tab
* that can be used to switch to a page in the TabbedFolder.
*/
public /*final*/ class TabItem extends Item {
TabFolder parent;
int x,y,width,height = 0;
String toolTipText;
Control control; // the tab page
// internal constants
static final int LEFT_HORIZONTAL_MARGIN = 8;
static final int RIGHT_HORIZONTAL_MARGIN = 2;
static final int VERTICAL_MARGIN = 1; // space between tab shadow and tab content
static final int ICON_MARGIN = 6;
static final int SHADOW_WIDTH = 2; // width of the tab shadow
static final int DEFAULT_TEXT_WIDTH = 36; // preferred text width if there is no text.
// Used for preferred item width calculation
/**
* Construct a TabItem with the specified parent and style.
*/
public TabItem (TabFolder parent, int style) {
this(parent, style, parent.getItemCount());
}
/**
* Construct a TabItem with the specified parent and style, inserted at
* the specified index.
*/
public TabItem (TabFolder parent, int style, int index) {
super (parent, style);
parent.createChild (this, index);
addListener(SWT.Dispose, new Listener() {
public void handleEvent(Event event) {disposeItem();}});
}
protected void checkSubclass () {
if (!isValidSubclass ()) error (SWT.ERROR_INVALID_SUBCLASS);
}
/**
* Dispose the receiver.
*/
void disposeItem () {
parent.destroyChild(this);
parent = null;
control = null;
toolTipText = null;
}
/**
* Expand the receiver's bounds by the specified number of pixels on
* the left,top,right,and bottom.
*/
void expand(int left, int top, int right, int bottom) {
if (hasLocation()) {
x = x - left;
y = y - top;
width = width + left + right;
height = height + top + bottom;
}
}
/**
* Return the bounds of the TabItem.
*/
Rectangle getBounds () {
return new Rectangle(x, y, width, height);
}
/**
* Gets the control.
* <p>
* @return the control
*
* @exception SWTError(ERROR_THREAD_INVALID_ACCESS)
* when called from the wrong thread
* @exception SWTError(ERROR_WIDGET_DISPOSED)
* when the widget has been disposed
*/
public Control getControl () {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
return control;
}
/**
* Answer the display of the receiver's parent widget.
*/
public Display getDisplay() {
if (parent == null) error(SWT.ERROR_WIDGET_DISPOSED);
return parent.getDisplay();
}
/**
* Return the parent of the TabItem.
*/
public TabFolder getParent () {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
return parent;
}
/**
* Gets the tool tip text.
* <p>
* @return the tool tip text.
*
* @exception SWTError(ERROR_THREAD_INVALID_ACCESS)
* when called from the wrong thread
* @exception SWTError(ERROR_WIDGET_DISPOSED)
* when the widget has been disposed
*/
public String getToolTipText () {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
return toolTipText;
}
/**
* Answer true if the receiver has been layed out.
*/
boolean hasLocation() {
return !(width == 0 && height == 0 && x == 0 && y == 0);
}
/**
* Answer the image height.
*/
private int imageHeight() {
Image image = getImage();
if (parent.getImageHeight() != -1) {
return parent.getImageHeight();
} else if (image != null) {
return image.getBounds().height;
}
else {
return 0;
}
}
/**
* Answer the icon width.
*/
private int imageWidth() {
Image image = getImage();
if (image != null) {
return image.getBounds().width;
} else {
return 0;
}
}
/**
* Paint the receiver.
*/
void paint(GC gc, boolean isSelected) {
// high light colored line across left and top
gc.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_HIGHLIGHT_SHADOW));
gc.drawLine(x, y + height - 2, x, y + 2);
gc.drawLine(x, y + 2, x + 2, y);
gc.drawLine(x + 2, y, x + width - 3, y);
// light color next to the left and below the top line.
// Since tabs expand horizontally when selected, we actually draw
// the background color to erase any debris from a selected tab.
gc.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_LIGHT_SHADOW));
gc.drawLine(x + 1, y + height - 2, x + 1, y + 2);
gc.drawLine(x + 2, y + 1, x + width - 3, y + 1);
// dark colored line at right
gc.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_FOREGROUND));
gc.drawLine(x + width - 1, y + 2, x + width - 1, y + height - 1);
// dark pixel on top of shadowed line, inside dark line
gc.drawLine(x + width - 2, y + 1, x + width - 2, y + 1);
// shadowed line on right inside the dark line
gc.setForeground(parent.getDisplay().getSystemColor(SWT.COLOR_WIDGET_NORMAL_SHADOW));
gc.drawLine(x + width - 2, y + 2, x + width - 2, y + height - 1);
// icon and bitmap. Should probably be checking style bits to determine
// exactly what to paint. Do we just draw the icon when the icon/text combination
// is too wide to fit all tabs?
gc.setForeground(parent.getForeground());
int xDraw = x + LEFT_HORIZONTAL_MARGIN;
int yCenter;
int decorationHeight = SHADOW_WIDTH * 2 + VERTICAL_MARGIN * 2;
Image image = getImage();
Rectangle sourceBounds = null;
if (image != null) {
sourceBounds = image.getBounds();
yCenter = y + SHADOW_WIDTH + VERTICAL_MARGIN + (height - decorationHeight - imageHeight()) / 2;
gc.drawImage(
image,
sourceBounds.x, sourceBounds.y, sourceBounds.width, sourceBounds.height,
xDraw, yCenter, sourceBounds.width, parent.getImageHeight());
}
xDraw = xDraw + ICON_MARGIN;
if (sourceBounds != null) {
xDraw += sourceBounds.width;
}
yCenter = y + SHADOW_WIDTH + VERTICAL_MARGIN + (height - decorationHeight - textHeight(gc)) / 2;
gc.drawString(getText(), xDraw, yCenter);
}
/**
* Answer the preferred height of the receiver for the GC.
*/
int preferredHeight(GC gc) {
int height = textHeight(gc);
if (imageHeight() > height) height = imageHeight();
height += VERTICAL_MARGIN * 2 + SHADOW_WIDTH * 2;
return height;
}
/**
* Answer the preferred width of the receiver for the GC.
*/
int preferredWidth(GC gc) {
return imageWidth() + textWidth(gc) + LEFT_HORIZONTAL_MARGIN +
RIGHT_HORIZONTAL_MARGIN + ICON_MARGIN + SHADOW_WIDTH * 2;
}
/**
* Sets the control.
* <p>
* @param control the new control
*
* @exception SWTError(ERROR_THREAD_INVALID_ACCESS)
* when called from the wrong thread
* @exception SWTError(ERROR_WIDGET_DISPOSED)
* when the widget has been disposed
*/
public void setControl (Control control) {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
if (control != null && control.parent != parent) {
error (SWT.ERROR_INVALID_PARENT);
}
Control oldControl = this.control, newControl = control;
this.control = control;
int index = parent.indexOf (this);
if (index != parent.getSelectionIndex ()) {
if (newControl != null) newControl.setVisible(false);
return;
}
if (newControl != null) {
newControl.setBounds (parent.getClientArea ());
newControl.setVisible (true);
}
if (oldControl != null) oldControl.setVisible (false);
}
/**
* Sets the image.
* <p>
* @param image the new image (or null)
*
* @exception SWTError(ERROR_THREAD_INVALID_ACCESS)
* when called from the wrong thread
* @exception SWTError(ERROR_WIDGET_DISPOSED)
* when the widget has been disposed
*/
public void setImage (Image image) {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
Image oldImage = this.image;
super.setImage(image);
if (image == null || !image.equals(oldImage)) {
parent.itemChanged(this);
}
}
/**
* Set the widget text.
*
* PARAMETERS
*
* string - the new label for the widget
*
* REMARKS
*
* This method sets the widget label. The label may include
* the mnemonic characters but must not contain line delimiters.
*
**/
public void setText (String string) {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
String oldText = text;
if (string == null) error (SWT.ERROR_NULL_ARGUMENT);
super.setText(string);
if (!string.equals(oldText)) {
parent.itemChanged(this);
}
}
/**
* Sets the tool tip text.
* <p>
* @param string the new tool tip text (or null)
*
* @exception SWTError(ERROR_THREAD_INVALID_ACCESS)
* when called from the wrong thread
* @exception SWTError(ERROR_WIDGET_DISPOSED)
* when the widget has been disposed
*/
public void setToolTipText (String string) {
if (!isValidThread ()) error (SWT.ERROR_THREAD_INVALID_ACCESS);
if (!isValidWidget ()) error (SWT.ERROR_WIDGET_DISPOSED);
toolTipText = string;
}
/**
* Answer the text height.
*/
private int textHeight(GC gc) {
String text = getText();
if (text == null) {
return 0;
} else {
return gc.stringExtent(text).y;
}
}
/**
* Answer the text width.
*/
private int textWidth(GC gc) {
String text = getText();
int textWidth = 0;
if (text != null) {
textWidth = gc.stringExtent(text).x;
}
if (textWidth == 0) {
textWidth = DEFAULT_TEXT_WIDTH;
}
return textWidth;
}
}
